A Comprehensive Analysis of Inductor Current Ripple and Filter Design for Three-phase Three-Level Grid-Tie Inverter

In this paper, the distribution of inductance current ripple in Neutral Point Clamped (NPC) inverters is described comprehensively. For different modulation index, the maximum current ripple in a line period is obtained, and the analytical formula for the peak inductor current under different power factors is given. Furthermore, the differences of inductance current ripple based on SPWM and DPWM1 modulation are compared. Finally, simulation results are presented to verify the theoretical analysis.